The amount of glucomannan shown to be effective as a laxative is 3–4 grams per day. Effective amounts for lowering blood cholesterol have been 4–13 grams per day. For controlling blood sugar, 500–700 mg of glucomannan per 100 calories in the diet has been used successfully in controlled research. For weight loss, 1 to 3 grams before each meal has been effective. When using glucomannan and other dietary fiber supplements, it is best to start out with a small amount and increase gradually. It is recommended to drink at least 8 ounces of water each time any bulk-forming laxative, including glucomannan, is taken.